Safety-valve



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A. G. MMmm?. SAFETY VALVE.

" No. 274L133. Patented Ma1n20, 1883.

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UNITED STATES PATENT OFFICE.

ALBERT C. MEADY, OF EAST SOMERVILLE, ASSIGNOR '.l() THE CROSBY STEAM GAGE AND VALVE COMPANY, OF BOSTON,MASSACHUSETTS.

SAFETY-VALVE.

SPECIFICATION forming part of Letters Patent No. 274,133, dated March 20, 1883.

Application filed January 2, 1883; (No model.)

To all whom it may concern; Be it known that I, ALBERT CEOIL MEADY, of EastSomervillegin the county of Middlesex, ofthe State of Massachusetts, have invented a new and useful Improvement in Safety-Valves for Steam-Boilers; and Ido hereby declare the same to be described in the following specification and represented in the accompanying drawings, of whlch- Figure 1 is a front elevatiomahd Fig. 2 a vertical section, ofasafety-val\'e provided with my invention, the nature of which is defined in the claim hereinafter presented.

In the drawings, A denotes the valve and seat-carrier, thevalve-seat of which is shown at a and the valve at b. Surrounding the valve and extending up from the said carrier is a tubular case, B, which is open at top, and having within it, arranged concentrically., a hub, o, supported by arms d, radiating from it to the said case. A tubular screw, C, screws downward through the said hub and against a washer, D, resting upon ,the upper end of a spiral spring, E. The said spring encompasses a spindle, Ff. and rests on a shoulder or circular' shelf, Gr, projecting from the spindle, and concentric therewith. The spindle at its foot is stepped upon the valve or rests in a step, d', formed therein, and the spindle at its upper part extends within the bore of the tubular screw G. By means of the said screw the spring may he contracted,so as to vary the pressure on the valve, as occasion may require. Such is a common method of constructing a safety-valve.v

My invention is for the purpose of forcing upward the valve-spindle and holding it up when raised,and'therefore,in carrying out my said-invention, I combine with the valve and its pressure-spring means or mechanism not only for contracting the spring, in order that the valve may rise under pressure ot' steam against it, but for' automatically holding the spring socontracted for any desirable period. To this end I fulcrutn to the case B a kneelever, H, and arrange it, as shown, so that its shorter arm shall extend through a hole, 7c, into the case and project directly underneath thespring rest or shelf G. Through the longer arm of such lever I screw a screw, I, so that the inner end of such screw shall hear against the case B. 0n turning or screwing up the iscrew, the shelf G and its spindle may Vhe forced upward, so as to contract the spiral spring and relieve the valve ot' the pressure of ranged, adapted, and to operate substantially as set forth. Y

ALBERT GEO-1L MEADY.

Witnesses:

R. H. EDDY,

E. B. PRATT. 

